Die casting machine



Jan. 2, 1940. E. s. BIRD DIE CASTING MACHINE Filed Oct. 8, 1937 2Sheets-Sheet 1 @NN Q m Ina-52%;:- Edward fifizrd (12:24 ZMW PatentedJan. 2, .1940

UNITED STATES DIE CASTING MACHINE Application October 8,

8 Claims.

The presentinventlon relates to a die casting machine and particularlyto an arrangement of the passage by which the "molten material isdirected to the dies, the machine being. especially .3 useful in castingstereotype plates.

In the die casting of metals having a relatively low melting point, themachine provides for the distribution from a melting pot to the diethrough a relatively slender goose neck, in' which, if the i metal isnot heated to a high temperature in the pot, there is a tendency for thematerial to solidify before it'can reach the dies. One of the objects ofthe present invention; is to provide an" arrangement by which metalpassing from the l: melting pot to the die may be kept at a suitabletemperature by a provision for heating the material as it passes throughthe goose neck.

Where the material is to be cast in relatively thin plates, as in thecasting of electrotype plates, '1 if the'materia'l enters the diesthrough a relatively small nozzle, as in the usual construction, it iscooled before it can fill the entire opening in the die and anon-uniform plate, or a partially formed plate results. -A I furtherobject of the 5 present invention is to so arrange the goose neck anddies that the molten material will enter the dies in a relatively widefilm and will be directed to the entire area of the die before thematerial solidifies or becomes too cool to flll all the intero stices ofthe die. 5

Other and furtherobjects and advantages of the invention willhereinafter more fully appear from the following description taken inconnection with the accompanying drawings in which- 11 Fig. l is asectional-view through a die casting machine embodying the invention.

Fig. 2 is a plan view of the device of Fig. 1'. Fig. 3 is a sectionalview along the line 3-3 of Fig. 1.

. Fig. 4 is a sectional view along the line 4- -4 of Fig. 1 I

With reference first to Fig. l, the machine comprises a base I which issuitably mountedon a foundation 2 which supports a burner 3, of well 4.known construction, for heating the metal in the melting pot. The baseis lined with suitable fire brick or other insulating material, and hasan integral portion la to which the lower die is secured as by suitablebolts 4.

the metal to be used in the die casting and this metal is kept in amolten condition by the heat from the burner 3, above which the pot 5 ispositioned. The melting pot has a projecting flange 55 G which rests onthe upper edge of the base I A melting pot 5, in the form of a cup,receives Edward S. Bird, Worcester, Mass, asslgnor to Reed-PrenticeCorporation, Worcester, a corporation of Massachusetts Mass 1931, SerialNo. 168,049 a and is secured thereto by suitable bolts. The melting pothas an integral vertical cylinder 1, in which is located a piston 8. Theupper edge of the cylinder has one or more notches 9 provided. thereinto allow the molten metal in the pot to flow into the cylinder when thepiston ,8 is] elevated to uncover a part of the notch. The piston 8 ismoved vertically by any suitable mechanism of well known construction,which may be a fluid actuated motor in the form of a cylinder and pistonlocated above the melting pot.

From the lower end of the cylinder 1 the melting pot is provided with apassage III which extends diagonally upward toward the dies where IIIthe material is to be cast. This passage It) forms a part of the gooseneck, and as shown in Figs. 2 and 4, is substantially equal in width, atthe bottom, to the diameter of the cylinder 1, and is relatively narrowvertically to define an elongated slot. As the passage l0 approaches the20 upper end thereof, the vertical dimension of the passage decreasessubstantially and the horizontal dimension increases substantially (seeFig. 3) tocause the molten metal passing through the goose neck toassume gradually a thinner 95 and thinner web, which by reason of itsthickness, can be heated rapidly by the hot gases from the burner.

As shown, the underside of the pot 5 beneath the passage extendsdiagonally upward sub- 0 stantially parallel to the passage and isspaced from the brickwork to allow hot gases to move upwardly directlybeneath the passagefor heating the metal therein. The upper end of thepassage l0, which is a relatively long narrow 35 slot, communicates witha similar shaped passage vll'in the lower die l2, this passage alsoextending diagonally upward in line with the passage Ill. The passage H,which at its connection with the passage I0, is similar in shape.continues to become more narrow vertically, and wider horizontaly, to anopen end IS in the upper surface of the lower die. At this point thepassage H is equal in width substantially to the width of the plate tobe cast, and communicates with a passage ii between the upper and lowerdies which extend the entire width of the opening in the die. An arcuaterecess M in the upper die it defines the upper surface of the passage Iiwhich is a continuation of the passage II. The lower surface of thepassage is defined by a hardened steel insert IS in a recess IS in thelower die. The upper surface of this insert cooperates with the recess14 in defining the passage H which gradually decreases in thicknessburner that heats the pot.

until it is less than the general thickness of the plate to be cast.Thus, after the casting operation, the completed plate may be brokenaway from the material in the passage H' along one edge of the platewhere the hardened insert has substantially reduced the thickness of thecasting.

The arrangement for separating the dies after the removal of cast platesand for holding the dies together during the casting operation may be ofany suitable character, and may operate, if desired, in timed relationto the vertical movement of the piston 8. The timed relation allows thedies to remain together after the material has been forced between thedies for a sufiicient time for the material to cool and solidify andpressure is then relieved by vertical movement of the piston 8 beforethe dies are separated. The upper die I6 is obviously mounted on avertically movable head I! for opening or closing the dies.

It will be noted that the melting pot cooperates with the lower die informing a receptacle for molten metal in which the metal may besubstantially the height of the open end of the passage II in the lowerdie, as shown in Fig. 1, so that metal in the passages l0. and H willremain in a molten condition throughout the entire length of thepassage, especially when the heat from the burner which keeps thematerial in the cup molten is directed upwardly beneath the passages l0and II for heating the latter.

The machine is especially useful in casting stereotype plates, and forthis purpose, as shown in Fig. 1, the lower die l2 has a recess, 18,Figs. 1 and 2, in which a matrix I9 is positioned, the latter thendefining the lower surface of the opening 20 in the dies in which thestereotype plate is cast. The molten metal flows over the matrix andfills all the interstices in the dies under the influence of thepressure exerted by the piston 8. It will be apparent that, when thedies are closed, the adjacent surfaces of both upper and lower dies arein engagement around the entire periphery of the openings therein toconfine the molten metal during the casting operation. 7

In order that the passage may retain its shape under heavy pressures ofthe molten metal in the passages Ill and II, the passage l0 may have oneor more integral webs 2| which are shaped to impede theflow of metal aslittle as possible.

In the operation of the machine, the piston 8 having been raised toallow molten metal to flow into the cylinder 1 and passages l0 andv I I,the dies are brought together,' as shown in Fig. 1. The piston 8 is thenmoved downwardly into the cylinder, forcing the molten metal through thepassages H and II and into the opening in the dies above the matrix.Since the passage H is coextensive laterally with the opening in' thedies the molten metal is directed between the dies in the form of a weband can thus be forced into all the small interstices of the matrix andupper die before it cools too much to flow.

From the foregoing it will be apparent that the present inventionprovides, in combination with a melting pot, a passage communicatingwith the pot and heated directly by the same ,The passage whichgradually becomes wider horizontally and thinner vertically, to assurethe metal remaining sufficiently hot, has its upper end only slightlyabove the level of the metal in the pot and the passage is thussubstantially filled with molten metal at all times. The passage allowsthe metal to enter the dies. above the matrix in a thin web as wide asthe entire width oi the matrix, and, in combination with the hardenedinsert IE, to provide for breaking the plate away from the hardenedmetal in the passage H.

I claim,

1. In a die casting machine, upper and lower dies efining therebetween arecess in which a relatively wide plate is cast, a plunger for forcingthe material to be cast into the recess, and a member having a passageproviding a connection from the plunger to the dies, said passagegradually increasing in width toward the dies with the end of thepassage adjacent the dies substantially as wide as the recess therein,the lower of said dies having a passage communicating and in line withthe passage in the member, said passage in the lower die extending fromthe underside to the top thereof.

2. In a die casting machine, .upper and lower dies defining therebetweena recess in which a relatively wide plate is cast, a plunger for forcingthe material to be cast into the recess, a member having a passageproviding a connection from the plunger to the dies, said passagegradually increasing in width toward the dies with the end of thepassage adjacent the dies substantially as wide as the recess therein,the lower of said dies having a passage communicating and in line withthe passage in the member, said passage in the lower die extending fromthe underside to the top thereof, and a hardened insert in one of saiddies coextensive in length with the adjacent edge of the recess in whichthe material is cast, said insert being adjacent to and extendingparallel to the upper end of the passage in the lower die. g

3. In a die casting machine, a base, cooperating dies, one of which ismounted on the base, a melting pot on the base, said pot having anupwardly slanting passage therein providing a connection from the pot tothe dies, the die on the base having an upwardly slanting passage com.-municating with the passage in the melting pot and in line therewith,said passage in the die extending from the underside to the top of saiddie, with the upper end of the passage in the die substantially on thelevel with level of the molten material in the pot.

4. In a die casting machine, a base, cooperating dies, one of which ismounted on the base, a melting pot on the base, said pot having acylinder therein in which a plunger is slidable, and said melting pothaving a passage therein extending upward from the lower end of thecylinder, the die on the base having'a passage communicating with theupper end of the passage in the melting pot and in line therewith, saidpassage in the die extending from the underside to the top thereof, theupper end of the passage in the die being only slightly above the normallevel of the molten material in the pot.

5. In a die casting machine, a base, cooperating dies, one of which ismounted on the base, a melting pot on the base, said pot having acylinder therein in which a plunger is slidable, and said melting pothaving a passage therein extending upward from the lower end of thecylinder, the die on the base having a passage communicating with theupper end of the passage in the melting pot and in line therewith, saidpassage in the die extending from the underside to passage in the potbecoming thinner as it approaches its the top thereof, said graduallyWider and the normal 7 said melting pot upper end, and reinforcing websin the passage to prevent distortion thereof.

6. In a die casting machine, a base, cooperating dies, one of which ismounted on the base, a melting pot on the base, said pot having acylinder therein in which a plunger is slidable, and

having a passage therein extending upward from the lower end of thecylinder, the die on the base having a passage communicating with theupper end of the passage in the melting pot and in line therewith, saidpassage in the die extending from the underside to the top thereof, theupper end of the passage being partially defined by an insert in one ofthe dies, said insert being substantially equal in length to the widthof the recess in the dies in which the material is cast.

'1. In a die casting machine, a base, cooperating dies, one of which ismounted on the base, a melting pot on the base, said pot having acylinder therein in which a plunger is slidable, and said melting pothaving a passage therein extending upward from the lower end of thecylinder, the die on the base having a passage communicating with theupper end of the passage in the melting pot and in line therewith, saidpassage in the die extending from the underside to the top thereof, 7sage being defined by a hardened insert in one of the dies and anarcuate recess in the other die, with the extreme end of the passagethinner than the general thickness oi the plate to be cast. v

8. In a die casting machine, a base, upper and lower dies defining arecess therebetween, the lower die being mounted on the base, a meltingpot on the base, said pot having a cylinder therein in which a plungeris slidable, said pot having a passage providing a connection from thecylinder to the lower die, the lower die having a passage providing aconnection from the upper end of the passage in the melting pot to therecess in the dies, said passage in the die extending from the undersideto the top thereof, said lower die having a recess to receive a matrix,an insert in the lower die at the edge of said recess at least as longas the width of the recess, the upper surface of the insert being inline with the upper end of the passage in the lower die and beingcoextensive therewith, to form a continuation or the passage.

EDWARD S. BIRD.

the upper end the pas-

